Method of up-dating the contents of the electronic memory of an electronic appliance

ABSTRACT

To update the memory contents in an electronic memory formed by an EPROM (4) in an electronic apparatus (5) without hardware measures, communication is initiated between the electronic apparatus (5) and a data processing system (1), whereupon code (6) corresponding to the program code of the apparatus (1) is loaded from the data processing system (1) into a RAM (7) assigned to the EPROM (4) of the electronic apparatus (5). After activating the program code (6) loaded into the RAM (7) and initiating communication between the RAM (7) and the data processing system (1), the EPROM (4) is erased. Then the up-to-date memory contents are loaded from the memory (2) of the data processing system (1) into the EPROM (4) and a reset signal is generated.

FIELD OF THE INVENTION

The invention relates to a method of updating the contents of theelectronic memory of an electronic apparatus, where the up-to-datememory contents are transmitted to the memory of the electronicapparatus from a data processing system which has the up-to-date memorycontents and is connected to the electronic apparatus via a serialinterface.

BACKGROUND INFORMATION

IBM Technical Disclosure Bulletin, vol. 37, no. 03, March 1994, page 503describes a conventional method of updating the erasable programmableread-only memory of an electronic device. With this conventional method,an additional erasable programmable read-only memory module is usedwhich initiates communication with a data processing system connected toit for updating the memory contents of the first erasable programmableread-only memory module. Then a new program code is loaded into a largebuffer (which may be RAM) via the additional read-only memory module,and the one read-only memory module is also erased. Then the new programcode is loaded from the large buffer into the one read-only memorymodule.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a method of updatingthe contents of an electronic memory. The contents of an electronicmemory designed as an erasable programmable read-only memory of anelectronic apparatus can also be updated.

This object is achieved according to the present invention with a methodwhere program code corresponding to the program code and the programcode loaded into the random-access memory are loaded into arandom-access memory provided with the erasable programmable read-onlymemory of the electronic apparatus, and the program code loaded into therandom-access memory is activated, thus initiating communication betweenthis memory and the data processing system. Initiation of communicationcauses the erasable programmable read-only memory to be erased, and theup-to-date memory contents are loaded from the memory of the dataprocessing system into the erasable programmable read-only memory, andthe data processing system causes a RESET to occur.

An advantage of the method according to the present invention is thatthe contents of an erasable programmable read-only memory can be updatedwith it even when loaded with all or part of the program code of theelectronic apparatus. This does not require the replacement of therespective erasable programmable read-only memory in the electronicapparatus, nor is any other hardware measure necessary to update thememory contents in the method according to the present invention.

In an exemplary embodiment of the method according to the presentinvention, an EPROM with at least one area that can be excluded fromerasing is used as the erasable programmable read-only memory, andcommunication between the EPROM and the data processing system takesplace using a subprogram that is stored in the area of the EPROM thatcan be excluded from erasing. The advantage of this method is that, in astate in which the EPROM has already been erased and the RAM has alsobeen unloaded due to a power failure, for example, communication fromthe electronic apparatus or the EPROM to the data processing system canbe established with the help of the program stored in the area excludedfrom erasing, so that the method of updating the memory contents of theEPROM can also be readily begun again even in the above-mentioned stateof the memory of the electronic apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-6 show a schematic sequence of a method according to the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a personal computer 1 as the data processing system inwhose memory area 2 there is loaded a code 3, among other things, whichis provided for reprogramming an erasable programmable read-only memory4, designed as a flash EPROM, of an electronic apparatus 5; electronicapparatus 5 may be, for example, a protection apparatus for detectingfaults in electronic power supply equipment. Memory area 2 of personalcomputer 1 also contains a random-access memory (RAM) 6. Electronicapparatus 5 is also equipped with a RAM 7. The other electronic parts ofelectronic apparatus 5, such as a processor, are not shown in FIG. 1 orthe following figures.

At the start of the sequence of the method according to the presentinvention as illustrated in FIG. 1, communication is initiated betweenpersonal computer 1 and erasable programmable read-only memory 4 ofelectronic apparatus 5, wherein electronic apparatus 5 is identified andthe baud rate is set.

FIG. 2 illustrates how, in the next step after initiating communication,a program code containing the commands for the sequential program ofelectronic apparatus 5 is loaded from RAM 6 of personal computer 1 intoRAM 7 of electronic apparatus 5. A check is also performed.

FIG. 3 shows that after loading the program code from RAM 6 of personalcomputer 1 into RAM 7 of electronic apparatus 5, the code in RAM 7 isactivated. Then, as shown in FIG. 4, communication is initiated betweenRAM 7 of electronic apparatus 5 and personal computer 1, in the courseof which a check is performed to determine whether RAM 7 of apparatus 5has been loaded properly. Once this has been verified, the memorycontents of EPROM 4 of electronic apparatus 5 are erased.

Then, as illustrated in FIG. 5, the up-to-date memory contents or code 3is loaded from personal computer 1 into EPROM 4 of electronic apparatus5, so that the storage contents of electronic apparatus 5 are updatedwith regard to EPROM 4.

Finally, as shown in FIG. 6, a command from personal computer 1concludes the updating operation by generating a reset signal.

What is claimed is:
 1. A method of updating the contents of anelectronic memory device, the electronic memory device being designed asan erasable programmable read-only memory module and containing a storedprogram code, the method comprising the steps of:transmitting a programcode to the erasable programmable read-only memory module from a dataprocessing system, wherein the data processing system is connected tothe electronic memory device by a serial interface and wherein theprogram code is stored in a memory device of the data processing system;loading the transmitted program code into a random-access memoryassigned to the erasable programmable read-only memory module;activating the program code loaded into the random-access memory, andinitiating communication between the random-access memory and the dataprocessing system; erasing the erasable programmable read-only memorymodule; loading memory contents from the memory device of the dataprocessing system into the erasable programmable read-only memory; andcausing a reset of the electronic memory device by a signal from thedata processing system.
 2. The method according to claim 1, wherein anEPROM is used as the erasable programmable read-only memory, the EPROMincluding at least one area that can be excluded from erasing, andcommunication is initiated between the EPROM and the data processingsystem using a subprogram stored in the at least one area that can beexcluded from erasing.